1. Field of the Invention
The present invention generally relates to fixture and method for packaging MEMS devices, and more particularly to a wafer lever fixture which can be repeatedly used after the MEMS devices are packaged.
2. Description of the Related Art
Micro-electro-mechanical-system (MEMS) components are gradually applied to many electronic circuits and a variety of micro sensor. For example, the MEMS components can be electro-mechanical motors, radio frequency (RF) switches, pressure transducers and accelerometers.
U.S. Pat. No. 6,768,628, entitled “Method for Fabricating an Isolated Microelectromechanical System (MEMS) Device Incorporating a Wafer Level Cap”, discloses a structure of MEMS device, which includes a wafer lever cap for packaging a plurality of MEMS elements so as to protect the MEMS elements and to prevent the MEMS elements from the pollution of external dust. The wafer lever cap includes a plurality of caps, which are physically connected to each other. All caps must be mounted on the MEMS device, and then are separated from each other. However, U.S. Pat. No. 6,768,628 fails to disclose the process for separating the caps from each other.
Recently, a conventional method for packaging MEMS devices as follows. Referring to FIG. 1a, a base 10 is provided, wherein the base 10 has notch regions 14 located on the surface 12. Then, a photoresist 20 is formed on the base 10, and the photoresist 20 is patterned for exposing the notch regions 14. Referring to FIG. 1b, the notch regions 14 of the base 10 are etched for forming notches 16. Referring to FIG. 1c, a seed metallic layer 30 is formed on a part of the photoresist 20 located on the surfaces 12 of the base 10 and the notches 16 by a sputtering process. Referring to FIG. 1d, an insulating layer 40 is formed on the seed metallic layer 30, and the insulating layer 40 is patterned for exposing a part of the seed metallic layer 30 located on the notches 16. Referring to FIG. 1e, a metallic layer 50 is electroplated on the part of the seed metallic layer 30 located on the notches 16 so as to form caps 52. Referring to FIG. 1f, the caps 52 are physically connected to MEMS devices 60. Referring to FIG. 1i, when the base 10, the photoresist 20, the other part of the seed metallic layer 30 and the insulating layer 40 are etched, the caps 52 are reserved for packaging the MEMS devices 60.
However, steps of the conventional method for packaging the MEMS devices are complex, and they waste the material cost of the base, the photoresist, the other part of the seed metallic layer and the insulating layer.
Accordingly, there exists a need for fixture and method for packaging MEMS devices capable of solving the above-mentioned problems.